LOS ANGELES – The once booming singing competition TV genre has gone way off key with viewers. And if ratings don’t improve, sources tell FOX411 at least one long-running show could get the axe.

Let’s review the evidence.

The December finale of “X Factor” was down 45 percent from its previous season finale.

The finale of “The Voice” was down 20 percent year-over-year in the key 18-49 demographic.

“The Sing-Off” finale was also off almost 20 percent, and barely made that week’s top 20 shows (it was #20).

And now here comes the grand daddy of them all: “American Idol,” premiering on FOX January 15.

The show’s 12th season hit an all-time ratings low, averaging around 13.3 million viewers. Compare that to Season 5, when it peaked with 30.6 million average viewers, followed by 29.7 million for Season 6.

“The genre has become oversaturated and it’s a mockery of the music/entertainment business,” Allen Forrest, CEO of digital independent music company M. Republik Music Group, told FOX411. “When ‘Idol’ first launched in the United States, it was very exciting with its new concept and live voting process. Now it seems that every time I turn on the TV there is a new talent show competition, and some formats really lack originality.”

According to a well-placed industry source, change could be right around the corner. The insider told us that unless FOX loses one of its singing competition shows, or one of its Gordon Ramsey cooking shows, they have no slots available for new reality fare.

The network just hired three new people -- former Discovery executive Simon Andreae, Lisa Levenson and Alex Piper -- to develop new reality programming, so new show ideas should be hitting execs' desks.

Reps for FOX declined to comment.

Others, however, remain optimistic that the genre isn’t singing its swan song.

“I think there is some life left in the singing competition genre. It’s a genre that has been way over blown the last few years, but the core idea that anyone can be a star will always carry weight with U.S. audiences,” said Jed Smith, founder of music composition company Betafish. “The market for these types of shows will bounce back.”

Hollywood talent agent Alec Shankman agrees.

“Talent and singing competition shows have been around for decades, I don’t imagine they are going away completely anytime soon,” he said. “But like most formats, some down time certainly won’t hurt this type of show. I’m sure we will see a revival down the road featuring a bigger/better/louder version of the talent and singing competition.”

Hollie McKay has been a FoxNews.com staff reporter since 2007. She has reported extensively from the Middle East on the rise and fall of terrorist groups such as ISIS in Iraq. Follow her on twitter at @holliesmckay